Apparatus for rolling uniform gauge sheet or strip



Nov. 23, 1943. A. B. HASWELL I 2,335,061

APPARATUS FOR- ROLLING UNIFQRM GAUGE SHEETS 0R STRIPS Filed Aug. 14, 1941 2 Sheets-Sheet 1 hN/QN NM APPARATUS FOR ROLLING UNIFORM GAUGE SHEETS OR STRIPS Filed Aug. 14, 1941 2 Sheets-Sheet 2 Mae 5. war :24,

' mechanism in accordance with Patented Nov. 23, 1943 {UNITED STATES PATENT OFFICE APPARATUS FOR ROLLING UNIFORM GAUGE SHEET OR STRIP 2 Claims.

This invention relates to means for rolling sheet or strip stock in a continuous mill in such a manner that precise uniformity of gauge will be maintained throughout the entire length of the work.

Heretofore, when sheet or strip stock was hot rolled on a continuous mill, the head end of the strip was thinner than the tail end, the gauge gradually increasing from the head to the tail end. This lack of uniformity of gauge is undesirable and is an inherent disadvantage which arises in conventional prior practice because of the fact that the time interval required to pass a strip of great length through the mill is sufiicient to allow an appreciable cooling of the metal. Since the reduction in gauge varies with the temperature and the temperature of the strip gradually decreases from the head to the tail end, the

- reduction decreases in proportion, thus resulting in a wedge-shaped sheet or strip gradually tapering from the tail to the head end.

Accordingly, it is an object of the present invention to provide an improved apparatus which will produce a sheet of precise uniform gauge or thickness from end to end. This object is obtained by the use of the novel combination of apparatus hereinafter more fully shown, described and claimed.

' The invention may be practiced by utilizing conventional continuous mill apparatus in which one or more stands are slightly modified by the incorporation in the screw-down mechanism thereof of an auxiliary screw-down mechanism including a motor drive for the auxiliary screwdown mechanism connectable by a clutch .with the usual screw-down drive, this auxiliary being manually controlled. The-motor drive for the auxiliary screw-down mechanism is connected to the main screw-down drive in such a way as to permit the operation of the screws independently .of the main drive. For a more complete disclostands of a continuous hot strip mill.

Figure 2 is a plan view of one of the finishing stands equipped with the auxiliary screw-down vention. r

Figure 3 is a face view of the mill shown in Figure 2. 1

Figure 4 is an end elevation of Figure 3.' Referring in detail to the drawings, numerals I, 2, 3, 4, 6 and 6 represent conventionally sucthe present in-.

cessive roll stands of a continuous hot strip mill. The stands I to 4 inclusive, for example, may be of conventional form, equipped with conventional types of screw-downs for varying the space gap between the working rolls of the mills. Either of stands 5 or 6 may be regarded as a finishing stand, and either one of them may be equipped with the auxiliary screw-down mechanism hereinafter referred to in greater detail.

The work, in passing continuously through stands I, 2, 3 and 4, for example, will be slightly wedge-shaped from end to end, due to the time lag and temperature change above described. As the strip or sheet passes through finishing stands 5 and 6, the auxiliary screw-downs thereof arranged in accordance with the present invention will be caused to continuously decrease the gap between the rolls and thus eliminate the taper in the strip or sheet so as'to produce a finished product of precise uniform gauge from end to end.

Referring more particularly to Figures 2 to 4, inclusive, there is shown a conventional type of roll stand having up r and lower working rolls 1 and 8, backed up by backing rolls 9 and I 0. The upper backing rolls 9 are mounted in bearings ll slidably mounted in the mill housings and adapted to be forced downwardly by screw-down mechanism including the feedscrews l2 and I3.

The feed screw l2 has a gear l4 meshing with the worm IS on a shaft l6 which is connected by reduction gearing l1 and I8 with the armature shaft 26 of a powerful screw-down motor l9.

Similarly, the feed screw l3 carries a gear 2| which meshes with a worm 22 on a shaft 23 which is connected by reduction gears 24 and 25 with the armature shaft 26 of a powerful screw-down motor 21. The armature shafts 26 and 26 of the motors l9 and 21 are connectable with one another by means of a conventional magnetic clutch 26. The screw-down mechanism thus far described in detail is of conventional or standard form, and when the motors thereof are operated, is effective to force the upper backing roll 6 and upper working roll 1 toward the lower working roll 8 and lower backing roll l6, so as to control the gap or active pass between the working rolls. Each roll stand I to 6 inclusive may be assumed to be equipped with this standard form of screwdown. In addition, either one or both of the roll stands 6 and 6 may be assumed to be equipped with the auxiliary screw-down mechanism shown in Figures 3 and 4, to be presently described.

The auxiliary screw-down mechanism includes a screw-down motor of approximately 5 horse-- power, such as indicated at 30. The armature shaft of this drive for the auxiliary screw-down motor is connected by a suitable coupling 3| with a gear reduction unit 32 of the order of 100 to 1 reduction. The driven shaft 33 of this reduction unit has secured thereto a drive member 34 which coacts with a driven member 35 operatively coniary screw-down, the controller is shifted to running position. This starts the motor running idly but continuously, at low speed. By means of the rheostat, the motor is then brought to the requisite speed to eliminate the estimated variation of thickness of the strip coming, for example, from the roll stands I to 4 inclusive. When the head end of the strip has passed the stands 5 and 6 which are soon to be regulated by the auxiliary screw-down in accordance with the present invention, the operator closes an electric circuit which energizes the clutch 34-35, connecting the auxiliary drive to the main screwdown drive, thereby continuously turning the screws l2 and I3 at a predetermined rate. The auxiliary screw-down therefore continues to operate as long as the electric circuit is held closed by the operator. When the circuit is broken, the clutch 34-35 is disengaged and the screws stopped. In normal practice, the clutch will be held in engagement under control of the operator during the entire time interval that the sheet or strip is passing between the work rolls 1 and 8 of either or both of the finishing stands 5 and 6. At the beginning of each pass, the rolls of all The detailed disclosure herein contained is to be interpreted in an illustrative rather than a limiting sense, since various modifications and substitutions of equivalents may be made by those skilled in the art without departure from the invention as defined in the appended claims.

I claim:

1. A continuous rolling mill comprising a series of roll stands arranged in tandem, each stand comprising upper and lower working rolls between which the work passes successively, each stand having a motor-driven screw-down mechanism adapted to be intermittently actuated so as to adjust the active pass between the working rolls, at least one stand of rolls serving as a finishing stand, said finishing stand being equipped with an auxiliary motor-driven screw-down mechathe stands are set by means of respective screwdowns thereof. The main screw-down drive, magnetic clutch and brakes thereof are preferably so interlocked with the auxiliary screwdown drive that it is impossible to operate the .auxiliary drive when the main screw-down drive is in operation, and vice-versa.

From the foregoing, it will be manifestthat the;

nism, a gear reduction unit forming part of said auxiliary screw-down mechanism, and a manually controlled clutch between said gear reduction unit and the first-mentioned screw-down mechanism, the said parts being so constructed and arranged that the auxiliary screw-down mechanism of the finishing stand is operative during the passage of -work through the finishing stand to continually decrease the active pass in the finishing stand at a constant predetermined rate, whereby the inherent lengthwise taper in the work received from the preceding stands is continuously eliminated, thus providing a workpiece of uniform gauge from the head to the tail end thereof.

2. A rolling mill system includng, in combination, a series of stands arranged in tandem each having working rolls through which the work passes successively, eachstand including motorized screw-down mechanism for varying the active pass between the working rolls, one stand of the system constituting av finishing stand, said finishing stand including an auxiliaryscrew-down mechanism including a drive motor therefor, a reduction unit interposed between the said motor and the first-mentioned motorized screw-down mechanism, and a manually controlled magnetic clutch governing the operative connection between said auxiliary screw-down mechanism and the first-mentioned screw-down mechanism, the auxiliary screw-down mechanism being adapted to run continuously to constantly decrease the active finishing pass while the work is passing therethrough, whereby the inherent lengthwise taper in the work received from the preceding stands is'eliminated by the work rolls of the finishing stand, thus providing a workpiece of uniform gauge from the head to the tail end thereof. ARTHUR B. HASWELL. 

